单项选择题 You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. You create a Web form that contains the following code fragment：   <asp：TextBox runat="server" ID="txtSearch" />   <asp：Button runat="server" ID="btnSearch" Text="Search" OnClick="btnSearch_Click" />   <asp：GridView runat="server" ID="gridCities" />    You write the following code segment in the code-behind file：   01 protected void Page_Load（object sender， EventArgs e）   02 {   03   DataSet objDS = new DataSet（）；   04   SqlDataAdapter objDA = new SqlDataAdapter（objCmd）；   05   objDA.Fill（objDS）；   06   gridCities.DataSource = objDs；   07   gridCities.DataBind（）；   08   Session["ds"] = objDS；   09 }   10 protected void btnSearch_Click（object sender， EventArgs e）   11 {   12   13 }    You need to ensure that when the btnSearch Button control is clicked， the records in the gridCities GridView control are filtered by using the value of the txtSearch TextBox. Which code segment you should insert at line 12？（）

单项选择题 You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. You write the following code segment in the code-behind file to create a Web form：   01 string strQuery = "select * from Products；"   02   + "select * from Categories"；   03 SqlCommand cmd = new SqlCommand（strQuery， cnn）；   04 cnn.Open（）；   05 SqlDataReader rdr = cmd.ExecuteReader（）；   06   07 rdr.Close（）；   08 cnn.Close（）；    You need to ensure that the gvProducts and gvCategories GridView controls display the data that is contained in the following two database tables： the Products database table the Categories database table   Which code segment should you insert at line 06？（）

单项选择题 You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. You create a class that contains the following code segment：   01 public object GetCachedProducts（sqlConnection conn） {   02   03   if （Cache["products"] == null） {   04     SqlCommand cmd = new SqlCommand（   05       "SELECT * FROM Products"， conn）；   07     conn.Open（）；   08     Cache.Insert（"products"， GetData（cmd））；   09     conn.Close（）；   10   }   11   return Cache["products"]；   12 }   13   14 public object GetData（SqlCommand prodCmd） {   15   16 }    Each time a Web form has to access a list of products， the GetCachedProducts method is called to provide this list from the Cache object.  You need to ensure that the list of products is always available in the Cache object.  Which code segment should you insert at line 15？ （）